Web Form Fundamentals MacDonald Ch. 5

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Web Form FundamentalsMacDonald Ch. 5

• MIS 324
• Professor Sandvig

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Outline

• Web Forms
• Three sections
• Order of Execution
• Viewstate

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Web Forms

• Three Sections
• Page Directives
• Code Declaration Block
• Code Render Block

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1. Page Directives

• Set page properties
• Language, debugging, tracing,
• Import additional class libraries
• Common ones imported automatically
• Additional
• Database access, data manipulation, web services,
  drawing, communication

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2. Code Declaration Blocks

• Syntax
• ltscript runatservergt
• //Server-side code here
• lt/scriptgt
• Locate
• Anywhere on page ? usually at top
• Another file ? Code-Behind

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3. Code Render Block

• Contain
• HTML
• Text
• Server Controls
• Typically located below Code block
• Location does not affect output

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Code Render Block

• Can include ASP/PHP style tags
• Syntax lt strLastName gt
• Not used much in ASP.NET

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Outline

• Web Forms
• Three sections
• Order of Execution
• Viewstate

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Order of Execution

• .NET is event driven
• Events include
• Page load
• Button click
• checkbox checked
• textbox text changed
• etc.
• We write handlers (methods) to handle events
• Events fired in sequence
• Page Life Cycle overview (for the curious)
• Examples
• PostBack.aspx handout

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Outline

• Web Forms
• Three sections
• Order of Execution
• Viewstate

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ViewState

• Saves control data
• Encoded in hidden form field
• Benefit convenience
• Disadvantage
• Processing overhead
• Bandwidth
• NovusHR
• Turn off with
• EnableViewStatefalse
• Individual controls
• Page (in page directive)

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Summary

• .NET Framework
• Like a huge Lego set
• 5,000 types of pieces
• Mix and match pieces to build most anything
• Easily extended
• Add new classes
• Support for many languages platforms